File got corrupted while uploading in chunks to dropbox using API calls.

Impulsum Support The Dropbox API will accept whatever file data your app provides, exactly as it provides it; it will not perform any additional encoding or decoding. If you supply base64-encoded data, the uploaded data will still have that same base64 encoding. If you wish to upload a non-base64-encoded file, but your data is base64-encoded, you'll need to undo the base64 encoding first.

Otherwise, please refer to my earlier message in this thread for more information on debugging/writing code for this.